from machine import Pin,PWM
from utime import sleep,sleep_ms

red=PWM(Pin(23),freq=1000)
green=PWM(Pin(22),freq=1000)
blue=PWM(Pin(21),freq=1000)

while True:
    red.duty(1023)
    green.duty(0)
    blue.duty(0)
    sleep(1)

    red.duty(0)
    green.duty(1023)
    blue.duty(0)
    sleep(1)

    red.duty(0)
    green.duty(0)
    blue.duty(1023)
    sleep(1)